Google’s translation tool represents significant progress in the field of translation technology. Google Translate is free, fast, and more accurate than other online translation tools.

The bad news? It can’t rival skilled human translators when it comes to conveying all meaning accurately and naturally. When it encounters a word or phrase for which it lacks a sufficient number of translations, Google Translate may not produce the best translation, and may output a translation that is unnatural or simply wrong. Read on for RedLine’s take on the pros and cons of Google Translate.

The pros

Google Translate is fast. Incredibly fast. So fast that no human translator—or team of translators—can hope to compete with it in sheer output. A skilled human translator can translate an average of 2,000 words in an 8-hour day. Contrast that with the 2,000 words that Google Translate can convert in 0.8 seconds.

Google Translate uses a statistical learning approach, not a rules-based approach. The result is that many (but not all) translations are culled from human translations already online.

The cons

Google Translate makes mistakes. Malaysia’s Sun Daily newspaper recently reported on an interview that local media conducted with Google research scientist Ashish Venugopal. Venugopal explained why translation errors occur in Google Translate. He also discussed where the technology is headed.

Google Translate’s quality varies from language pair to language pair. The tool may produce a usable gist for an English-to-Spanish translation. Billions of words for each language can easily be found in cyberspace. Not so for Danish and Romanian. Or Turkish and Thai. Users who need a translation for rarer language pairs may find Google’s translation tool useless.

Google Translate doesn’t offer the user any form of quality control. The search giant’s massive market dominance leads user to implicitly trust its offerings. But a user has no way of knowing whether Google’s German translation of an English text is any good. Simply getting a result—any result—in no way guarantees the result is good.

The biggest negative to Google Translate is that it may produce a translation that is unnatural or simply wrong.

How does Google Translate work?

Google’s translation tool makes use of the search giant’s stupefying web-crawling capacity to enable its translations. This is different from other rules-based translation tools. Rules-based systems require substantial work from linguists, not to mention massive digital dictionaries. The result is an attempt at something close to word-for-word translation. Professional human translators know this just doesn’t work.

So what does Google do? Rather than use a rules-based system, Google Translate uses a statistical learning approach. It feeds billions of words (both monolingual text and “aligned” text that humans have translated) into its program. Then it lets the tool find popular matches.

The result? The tool can correctly translate the French phrase comme un éléphant dans un magasin de porcelaine into English: “like a bull in a china shop.” French speakers use éléphant and English speakers use “bull.” Different animals, same idea. By contrast, a rules-based approach to the same phrase might produce something like “an elephant in a porcelain store.” A native English speaker would recognize this word-for-word result as wrong.

Pros and cons of Google Translate: the verdict

So is Google Translate a useful tool? Yes and no. It depends entirely on your needs. A Fortune 500 company would risk its reputation as well as better sales figures if it relied solely on machine translation. It’s just not accurate enough to be used in commercial translation. But a high school student doing a research project may want to use it. It’s good at producing “gist” translations.

Users would do well to remember the pros and cons of Google Translate. The bottom line? It’s good for general, “low-stakes” translation. It’s not for professional use.

Matthew Kushinka is the founder and principal of RedLine Language Services LLC. Based in Grand Rapids, Michigan, the company helps commercial clients create, revise, and translate their written content. Send your questions or comments to matthew@redlinels.com or connect with Matthew on Google+, LinkedIn, Facebook, or Twitter.